The present invention relates to a digital copying machine and a digital copying machine system. More particularly, this invention relates to a digital copying machine and a digital copying machine system in which a high performance serial interface is used for an inner interface.
The technology of a high performance serial interface has been coming into wide use in recent years. For example, employment of a high performance serial interface such as a USB (Universal Serial Bus) and a bus (henceforth, xe2x80x9cIEEE 1394 busxe2x80x9d) defined in the IEEE standard for a High Performance Serial Bus (IEEE 1394-1995) [1] is recommended or obliged in the standard on PC 98[2].
The IEEE 1394 bus supports up to 400 Mbps, and it is planed to be further speeded up to 800 Mbps or 1.6 Mbps. The IEEE 1394 bus prepares an isochronous transfer mode in addition to an asynchronous transfer mode. This isochronous transfer mode has a function of previously reserving a band width to enable insurance of a transfer time for that mode. In the same mode, communications can be made by means of the asynchronous transfer using the remaining part of the bandwidth although the transfer time is not insured.
The USB is a general purpose bus which has been defined for the purpose of connecting between a PC and peripheral devices by a unified type of interface so as to make its handling simpler. In this standard, the bus is connectable with maximum 127 units and also supports a hot swap of the units. There are two types of transfer speeds such as 12 Mbps (full speed) and 1.5 Mbps (low speed), and it is possible to allow these speeds to be present on the same bus. The USB employs four types of transfer method of isochronous transfer, interrupt transfer, bulk transfer, and control transfer.
Another feature of these high performance serial interfaces is such that the interface has a function (hot swap) of enabling attachment or detachment of a unit in the state where the device actuated by a user is being active. In order to realize this function, the interface supports a function to notify, at the time of attaching or detaching any unit, the unit of that effect.
Digitization and a multifunctional level of a copying machine have been progressing in recent years. Progress in its digitization means that information transmitted between the units forming the copying machine is digitized. On the other hand, increase in its multifunctional level means that the number of units to be connected to the machine is increasing.
FIG. 13 shows the outline of an example of connection between units forming a multifunctional machine based on a conventional digital copying machine. In the figure, as an essential unit, an LDU (laser-drawing control unit) 402 which controls a drawing laser is connected to a MBD (motherboard) 401 which controls the overall units by a cable. As another essential units, there are also an SCU (scanner control unit) 403 which controls a scanner, an IPU (image processing unit) 404 which performs digital image processing, and a PCU (panel control unit) 405 which controls a panel, which are also connected to the MBD 401 via their respective cables.
As option units, there are a sorter unit 406, a paper tray unit 407, an ADF (auto document feeder) unit 408, and a manual feeder unit 409, which are connected to the MBD 401 via their respective cables. As another option units, there are an auto page-turning unit 410, a charging unit 411, a BRU (bill recognition unit) 412, a filing unit 413, a FAX unit (facsimile unit) 414, a PRTU (printer unit) 415, a paper turning-over unit 416, and an OCR unit 417, which are also connected to the MBD 401 by their respective cables. The cables which are used for connections between the MBD 401 and each of the units 402 to 417 are based on different standards for the units, respectively.
When the digital copying machine is to be formed to a multifunctional machine, most of the units are the option units, thus, it is desirable to easily attach the units to the machine by a user.
However, the conventional digital copying machine has prepared a different type of interface for each essential unit or option unit, which does not allow the user to easily attach the units to the machine. Therefore, an expert, who knows well the configuration of the digital copying machine, is required to attach or detach the essential units or option units to or from the machine. Thus, the attachment or detachment of the units to or from the machine is not easily carried out.
Further, since a plurality of signal lines are used for connections between the MBD 401 and the LDU 402 and between the SCU 403 and the MBD 401 based on speedup of the copying machine and multi-valued image data, there are some inconveniences as follows.
When a high-speed signal is transmitted through a plurality of signal lines, in association with an increase in the number of lines, a difference between times, at which the signal arrives in each of the signal lines, becomes a more serious problem (problems such as racing or skew). Based on the transmission, there are such problems:
1) the transmission clock rate can not be increased so much, and
2) the signal line can not be made so long.
The above mentioned first problem becomes an urgent matter because the digital copying machine has recently been speeded up. Whereas the above mentioned second problem includes a matter to be solved especially between the SCU 403 and the MBD 401 because, currently, the digital multifunctional machine tends to separate the scanner from the engine part in order to reduce the area of a place where the machine is installed or increase the flexibility in the place for its installation.
The present invention has been achieved in order to solve the above problems. It is an object of this invention to provide a digital copying machine and a digital copying machine system which can construct a system with a higher degree of flexibility by using a high performance serial interface as an inner interface.
According to one aspect of this invention, a scanner control unit reads an image of a document, a drawing control unit draws an image onto an image carrier, and a main control unit controls the overall machine. Further, a high performance serial interface is used as an inner interface.
Further, the drawing control unit and the main control unit are connected to each other by a high performance serial interface.
Further, the scanner control unit and the main control unit are connected to each other by a high performance serial interface.
Further, the scanner control unit and the drawing control unit are connected to the main control unit by their respective high performance serial interfaces.
Further, an image processing unit is connected to the machine by a high performance serial interface.
Further, a panel control unit is connected to the machine by a high performance serial interface.
According to another aspect of this invention, a scanner control unit reads an image of a color document, a drawing control unit is provided for each color in order to draw an image onto a latent image carrier in each color, and a main control unit controls the overall machine. Further, a high performance serial interface is used as an inner interface, and the main control unit and the drawing control units, each of which is provided for each color, are connected by their respective high performance serial interfaces.
Further, an option unit is connected to the machine by a high performance serial interface.
Further, the option unit is at least one among a sorter unit, a paper tray unit, an ADF unit, a manual feeder unit, an auto page-turning unit, a charging unit, a bill recognition unit, an OCR unit, a remote diagnosis unit, a filing unit, a facsimile unit, a printer unit, a hard disk drive unit, a removal disk unit, and a paper turning-over unit.
Further, the option units are connected to the machine by the same type of high performance serial interfaces.
Further, any control unit other than the option units controls the high performance serial interfaces.
Further, there are an isochronous transfer mode and an asynchronous transfer mode as a data transfer mode. Image data is transferred in the isochronous transfer mode, whereas a command is transferred in the asynchronous transfer mode.
Further, an IEEE 1394 bus is used as a high performance serial interface.
Further, a USB is used as a high performance serial interface.
Further, the main control unit is determined as a bus manager for the high performance serial interfaces.
Further, the main control unit is determined as a controller for the high performance serial interfaces.
Further, the digital copying machine is connected to an external device via a high performance serial interface and a bridge.
According to still another aspect of this invention, at least two of the above explained digital copying machines are connected to each other by a bridge via the high performance serial interfaces of the machines, and the bridge is configured so as to allow at least the two digital copying machines, which are connected to each other by the bridge, to perform a parallel operation.
According to still another aspect of this invention, at least two of the above explained digital copying machines are connected to each other by a bridge via the high performance serial interfaces of the machines, and the bridge is configured so as to allow, when one of the digital copying machines in operation goes down due to a breakdown or a paper jam or the like, the digital data of the disabled digital copying machine to be transferred to the other digital copying machine that is also connected to the bridge.
Further, a high performance serial interface is used as an external interface for the bridge.
Other objects and features of this invention will become apparent from the following description with reference to the accompanying drawings.